The present invention refers generally to an adapter for connecting at least two runner sections of a nozzle manifold of a hot runner injection molding system for distributing and conducting a flow of melt to the cavities or hot runner nozzles. More specifically, the present invention refers to an adapter of a type having a preferably rotationally symmetrical body exhibiting at least one end face connected to one of the runner sections and a cylindrical or conical wall surface connected to another runner section and extending at an angle with respect to the one end face.
Adapters of this type are known in a variety of designs, e.g. in European Patent Specification No. 0 226 798. Of interest are in particular those adapters for fluidly connecting runner sections of a hot runner system in a fluid-tight manner whereby the runner sections are aligned and/or angled to one another.
In general, conventional adapters have the disadvantage that one end of the runner section, e.g. the melt inlet opening or melt outlet opening, is formed in the flat end face while the second end exits at the cylindrical surface of the adapter. Although, conventional adapters can be so designed as to allow a sealing of mating plane surfaces of the adapter and the nozzle manifold by tightly clamping the adapter to the manifold body by means of suitable screw threads, such screw threads act however in only one direction so that the fluid-tightness of the cylindrical outer adapter surfaces depends solely on the quality of the fit between both sections whereby the fit should be so designed as to allow an easy disassembly of the adapter for cleaning purposes as well.